1. Field of the Invention
This invention relates generally to a tool for cutting the sealant from around the windshield of a vehicle when windshield replacement is desired, and more specifically to such a tool which includes a blade release mechanism for allowing quick release of a worn or broken blade and quick engagement of a new blade and which further provides a blade holder that allows substantial forces to be applied to the blade without substantial flexing of the blade relative to the blade holder.
2. Background of the Invention
Automotive vehicle windshields are typically held in place in the vehicle either by a urethane adhesive (applied directly to the vehicle) or by at least a partially resilient molding or gasket fitted in the windshield opening of the vehicle body and secured to the body. The gasket is typically formed to include an inwardly facing channel for receiving the edge of the windshield and preventing the windshield from being pushed either outwardly from the vehicle or inwardly. To further secure the windshield in the channel of the molding or gasket, an adhesive, sealant or bonding material is placed in the channel either before or after the windshield is installed to thus further secure the windshield in place in the gasket.
Because windshields become broken or cracked, it is often necessary from time to time to remove the windshield from a vehicle to replace it or to repair it. Then, either a new windshield is installed or the repaired windshield is reinstalled. In order to remove a windshield, it is necessary to cut or sever the bond between the windshield and the vehicle or windshield and the molding, as the case may be. A number of tools have been suggested for performing this cutting function. Typically, such tools include a blade extending outwardly from a handle for a short distance and then forming a right angle to the tip of the blade. The tip of the blade is inserted between the windshield and the vehicle or between the windshield and the molding, as the case may be. The blade is then pulled along the outer edge of the windshield from the outside of the vehicle to thereby sever the bond holding the windshield to the vehicle to allow the windshield to be removed.
When employing such a tool to cut the windshield from the vehicle, tremendous force is required to pull the blade along the outer edge of the windshield, making it difficult to maintain the blade in the proper cutting orientation, that is, to prevent the blade from wandering as it cuts. As such, many tools are provided with a pull handle that is attached directly to the blade with a cable or to the blade housing proximate where the blade exits the handle. In addition, because of the tremendous forces and stresses applied to the blade, it is common for the blade to fracture requiring replacement. One of the best tools for cutting the sealant from around a windshield is comprised of a cylindrical handle having an elongate slot formed therein for receiving a blade therein. Industry standard blades include three holes formed in the base or retaining portion thereof. The first two holes are secured to the handle with two externally threaded screws to hold the blade relative to the handle and to prevent the blade from rotating relative to the handle. A blade pulling handle is attached with a cable directly to the third hole in the blade. The third hole is positioned near the cutting portion of the blade to allow the pull handle attachment structure to clear the molding and windshield when the blade is inserted thereinbetween and to reduce the possibility that the pull handle attachment structure will contact the surface of the vehicle. While such a tool tends to perform well, it is very time consuming to replace the blade of such a device. Specifically, the two screws holding the blade to the handle must be removed as well as the pull handle attachment structure, and once a new blade is reinserted, the screws and pull handle attachment structure must be replaced.
Thus, it has been desirable to provide such a tool that allows for quick replacement of broken blades. One such tool that attempts to address these problems is described in U.S. Pat. No. 5,784,788 to Cothery. Cothery discloses a windshield replacement tool that allows for quick replacement of blades as well as a blade pull handle that is secured to the blade retaining member. However, the Cothery device has many drawbacks. To obtain enough clearance between the tool and the body of the vehicle to reduce the potential for scratching the paint of the vehicle, Cothery requires non-industry standard blades to be utilized, thus requiring special blades to be purchased. In addition, because of the use of the longer than standard distance between the point where the blade exits the handle and the ninety degree bend in the blade, the blade of Cothery tends to flex and thus wander as the blade is pulled around the windshield making it more difficult to cut and more likely that the blade will break. Moreover, because the cable of the pull handle rotates relative to the handle at an angle relative to the plane defined by the blade, it is more difficult to keep the blade cutting in a straight path. Finally, the cylindrical configuration of the blade holding portion and its blunt end makes it more likely that the end of the handle proximate the blade will contact the vehicle resulting in chipping or scraping of paint on the vehicle.
Thus, it would be advantageous to provide a vehicle windshield replacement tool that substantially rigidly holds the cutting end of the blade to prevent excessive flexing of the blade while cutting. It would also be advantageous to provide such a tool that allows the blade to be quickly removed and replaced when the blade becomes worn or broken. Moreover, it would be advantageous to provide such a tool that utilizes standard cutting blades available in the industry. It would also be advantageous to provide a vehicle windshield replacement tool that allows the tool, and more specifically the blade, to be pulled at a point directly on or adjacent the blade rather than on the handle. Furthermore, it would be advantageous to provide a vehicle windshield replacement tool that provides enough clearance between the handle and the vehicle body to reduce the possibility of damaging the surface of the vehicle. Additionally, it would be advantageous to provide a vehicle windshield replacement tool that is comprised of a plastic, nylon, or other non-metallic handle to reduce the possibility of scratching the paint of a vehicle if the handle contacts the paint during use of the tool.